Pressure-control switch



^ Feb. 26, 1929.

DQ P. HEATH PRESSURE CONTROL SWITCH 2 sheets-sheet 1 Filed July 22, 1926 Aorne,

Feb. 26, 41929. 1,703,235

' D. P. HEATH PRESSURE CONTROL SWITCH Filed July 22, 1926 2 Sheets-Sheet 2 7 2 4 Lg Y 4 Imam/ov 9' 23 9 Duos Pfecmn www5;

Pateyuedrebsze, 1929..

PATENT OFFICE.

minos P. HEATH, or PEOBIA, ILLINoIs.

PRESSURE-con VApplication ineaf .my 22,`

This invention relates to an automatic pressure control switch construction particu-v larly/adapted for use ,with mechanical re frigerating machines such as are used in reyfrigerators wherein an electricmotor is* cut y in or out so as to operate the refrigerating machine at the times when it is desired andstop it at other times. The pressure control system is/to be preferred over althermostatic lo con-trol as it is of more sturdy land durable construction and can ,bel quickly and accurately adjusted and is notsubject to such variations as isfthe temperature system s6 that the period ofI operation of the refrigercontolled.,

i It is vanobject and purpose of the present invention to construct a switch unit which may be conveniently used together with a fuse block and lfuses in a single control box and wherein a longitudinally expansible and contractible bellows is utilized, beingl expanded on increase of pressure and contracted on lowering thereof, such expansion beyond apredetermined amount acting automatically through a switch to start the motor i in operation and the contraction when the pressure has reached the desired stage snapping the switch so as to'break the circuit in which the motor is disposed and stop the machine from further operation until the ypressure has again raised to themaximum amount on the low pressure side of the systemto which the invention is applied. .A

further object and purpose .of the invention is to provide this switch with springs acting against the pressure ofthe longitudinally contractible and expansible element or bellows, as it is commonly known, which are 4o easily capable of adjustment for obtaining a f different rang when desired. A still further object of the invention is to construct a control box which while it completely7 encloses and covers the bellows, such be lows may be yery easily removed and replaced at anytime if it should be necessary without disturbing `the box other than to remove the cover over the bellows. Many other objects and purposes than those stated, particularly :juo the 4construction of the apparatusk in a practieal and economical manner using* sheet metal i parts to a large extent, will appearas under- '15 atinof machine is more accurately and better 1926. serial No. 124,190.l

standing of the invention -is had from the following description taken in connection with the accompanying drawings, in which Fig. 1 is anfel'evation of the control box llooking at the open side thereof and disclosing the switch mechanism and fuse block and fuses located within said control box.

Fig. 2 is a fragmentary longitudinal vertical section throughone end of the control box and theswitch mechanism located there- 1n wherein the mercury tube switch is replaced by a simple knife switch. 4

Fig. 6 is a View similar-to tht shown in Fig. 1 but-showing only'the switch structure at one end of the control box, said switch form.

Fig. 7 is a transverse vertical section -l through the control boxsatthe right of the switch. mechanism Jshown in'Fig. 6l and lookmechanism in elevation. Fig. 8 is a perspective View of the bellows cover plate, and4 1 Fig. 9 is a fragmentary transverse vertical section on the line 9-9 of Fig. 6.

Fig. 3 isr ai' fragmentary vertical section Like .reference characters refer tolike parts in the different figures of the drawings. 1

- The control box which is of any suitable l metal, preferably aluminum, has a vertical back 1, vertical ends Zand 3, a bottom 'side- 4, and a top side 5, all cast integrally. 'A lug or ear 6 projects upwardly from the ybottom 4 between whichand the back 1 a lever 8 sub-Y stantially of channel ^form is p ivotally mounted 'at its lower end on ythe pivot 7. From the flanges orV sides ofthe lever 8 substantially rectangular enlargements `9 Iextend to one side of the same-.having'openings 10 therethrough, as shown in Fig. 1. A rodl 1.1 extends through and is rotatably mounted on the back 1, at its outer side being equipped with a handle 11a turned at right angles while .the inner end portion of the` rod extends 75 structure. being of a somewhat -different`- so ing toward the left. to show. said switch'` s through the openings and a block 12 is fixed to the rod also extending through said one end so that a cam The K distance either way on the pivot 7, in another rod between said lever and the adj ustin of which the lever is held at exteme'left position, and in thethird position it is held atl extreme right position, as is evident.

A horizontalrod 13 passes through the end 210i the control box and then through the up-y perend of the lever 8.v AA coiled spring 14l the l and locating nuts 15 threaded ontolthe end 'of the rod. The outer end ofthe rodis equipped with a knurled head 13a by means of which it may be turned. The outer end portion isis located around the free end portion o j likewise threaded where it passes through the end 2 of the control box and arries a locating nut16 which bears against the outer side of the end 2, as shown. The spring 14,I it is evident, may be adjusted so as to be come pressed toa. greater or less degiee by the nuts 15 and the lever 14, the tendency thereof be- -ing'to move the lever toothe left, as shown in Figs. 1 and' 2. Adjustment mayalso be made by means of the nut 16 and head 13a; l

Between thesides of the lever 8 a distance below the rod 13 a cross bar 17 is integrally cast therewith hooked over` which is .one/end of a coiled tension spring 18. This springpis disposed horizontally. and extends toward 4the end 2 of the control box, at its outer end surg 'rounding and beingpermanently attached to asnut 19. A threaded rod 2() passes through a slot 21 in the end 2 of the box'and thence vis threaded through the -nut 19. At its outer end the rod is equipped with a head 22 so that `rod 20 may be adjusted inwardly or outwardly throughthe nut 19 and control the tension of spring 18 andthe force of thegpull that 1t At the lower cornersof the box between the end 2 and the lower portion of the lever 8 a corrugated metal bellows 23 subject tolongitudinal contraction or expansion, is located, both ends of which areV closed, the en d nearest the lever 8 being equippedl witha point 24 which titsfa suitable recess in the side of the lever 8 a shortdistance above the pivot 7. The opposite end of the bellows seats against a boss projecting inwardly from the end'2 of the control box through which a. short length of pipe .25 extends, the outer end of which is connected with a flexible jmetal p tube 26 through which ythe pressure at the lower side ofthe system is carried to the interior of the bellows. The pipe 25 is threaded at its outer and inner ends to'receive the nuts 27 i there bein tween the ss mentioned and the endvofthe a suitable gasket interposed bemally covered by end 1 two spaced apart sides 35 other as the line of vforce of the spring and 28,v

bellows and another between theiinner side l of the end of the`bellows and -said nut 28 so so that the bellows -with the attached parts '75 as readily removedand replaced without dis- 25 and 26 may be readily installed or maybe turb'ing the control box in any other Way even though it is permanently secured in place in connection with the refrigerating machine with which it is to work. This opening is nora coverl 30 arc shpped inv cross section .and is equipped with adapted to pass one above and the other below the pipe 25 and be clamped against the of the control box when the nut 27 is tightened. f i

.horizontally from the back 1 of the control tical spaced apart legs 33 connected' by a bottom ,34. A'second `U-shaped memberV of sheet metal is located at the upper end of the 'first of said members and is inverted having connected by a top 36. The sides 35 pass within the sides 33 of the first U-shaped member with anoutwardly extending lugA 37 which seats in a notch or recess in the adj acentside 33 of the lower member, A coiled spring 38 under tension is disposed between and connected at its ends 34 andthe top 36 of the two members, as bestl shown in Fig. 3. f

(The two sheet metal EU-shapedimeinbers.

described and mounted in the manner deupper movable member from one side tothe passes from one side to the other of the dead center line of the toggle.

respectively; to the bottoni? having ends, one ofl which two spaced apart fingers 31 post 32 is ca'st integrally and extends Vand each is formed llO . Above the toggle member described, a third y 'a rod 4l .which is attached to and projects `horizontally from theback 1 ofthe control 'box.\ A sleeve 42v isglocatedt around the'rod and properly positions the third U-shaped member A-directly over Vthe toggle. To the under side or bottom 40 of this member a member or otherwise permanently secured having a top side 44 which lies against the under side -shaped member of Ysheet. metal'is locatedC havmg two spaced apart sides 39 connected Yby a. bottom 40. Thls member 1s mounted on also formed of sheet metal is soldered of the bottom 40 and is secured thereto from i one edge ofwhich a web 45 extends downwardly, it at its vertical edges being formed with flanges 46 which'exten one l.to each side meegaat "ot the upperl movable member oi the toggle whereby when this upper movable member oi" the toggle is shifted troni one side to the other the construction pivotally mounted on the rod is turned aboutsaid rod from 'rient to lett and vice Versa.

.between sides 39 a glass tube 43 is clamped one end which are two spaced apart contact heads 47 connected respectively to the ends ot' two rods 48 and 48il which in turn areconnected to the wires 49 of the electric circuit which the motor i'or operating the c refrigerating machinerie placed. "Within the tuhe 43 quantity otniercurj indicated at is placed. and with the tilting oi the tuloe from one side to the other the mercury re'ely f "vs trom one end oi tlietuloe to the other. Aien is i 'he position shown in l it is evident that the circuit is broken inasmuch n as there is no electric connection lietweeri contacts 4i( n t when the tube is tilted to the opposite sideT as shown in Figa 3, lhot ot the` ls are partly immersed in the mercury nea and the circ*L @n one ot is closed.

member or 'the toggle a vertical channel" is secured aisee Fig.- 4). An arm 52 castintegral the lever 8 has'y au end portion4 53 turned at iight angles so as 'to pass between oit the spring 38 passes across the dead center4 line oil 'the toggle whereupon the tube 43 is snapped quickly from the position shown F 3 to that sliown in Fig. l with a resultant lorealr oit .the electric circuit and stopping oi the otor.` Conversely when the'pressure in the hellows 23 reduces permitting the torce of springs lf and i8 to more the lever to the lett with the contraction ot the hellows when the line ot torce oilspiing 38 crosses tlie dead center line or tlie toggle theswitcli will he snapped in the opposite direction, the

circuit completed and the motor started in oi3 switci iure shown the .mercury tube type es oi switches may lie used and in equivalent switcli^ for opening and struction the tuhe 43 and its connections and the llsliaped .nemher supporting the saine are ,eliminated and trom the w eh 45 or". the

n u 7 member engaging w 1th the upper inovahie other position l losing entirely disengaged e sides Bo oi the upper movable ligsrl, 2 and 3 it is olovious that' the circuit is disclosed. -ln such ,con-I therefrom. This is a simple type of lcniie l switch and is one which can he substituted ior the mercury tulie switch very readily.) the circuit wires being connected one with the contact and the other in any suitable manner, electrically connected .y with the plates 54. 'l'lie saine ellect in so/,ar as vstopping and starting theinotor `will he produced as with the mercury tube switch iirstdescrilied. v

ln Figs. 6 and 'Z a somewhat dierent or mooi tied iorm oi construction or the apparatus is shown. instead oi using the toggle construction such as shown in 3, at the end oi the post 32 two spaced apart horizontal. liars 56 are rigidly connected and held spaced apart relation :troni each other, these seri/'ing as a support for the pivotal mounting' oi switch carrying inenilier which is in the torre oi a casting having an upper hori- Zonta?. side 5'? from which two spaced apart legs 58 and tldepend hetween the hars 56 and are pivotally connected thereto. The

upper or tcp side 57 is extended to one side and then turned vertically as indicated at 60 while its opposite side the top V5'? is proridedwitli a horizontal har @l through which `two screws 62 pass the saine heinggadjust- 'able to dierent positions and lying direct-lg7 over the upper edge of one ol the hars 56.

The Vertical part 6G serves as a support ier "el-shapedclamping. memloer having sidese hetween which the glass tube 45 of thesame character as that shown in Figs.' l

and 3 though With Contacts at the oppositeY end, is clamped and secured. From the side or the' lever 8 an elongated projection 64 eirtends to which one `end ot a coiled spring '55 is secured7 the opposite end losing attached to the under side oit the top 5? of the switch carrying niemher.

This construction serves 't-lie same purposes as that shown in Figs. l, 2 and 3. As the lever 8 moves farther vtroni the position shown lin Fig. 6, to the right, witlitlie increaseoi pressure in the` bellows 23 the lower end o' H the spring 65 moves withcit and the line oi 'torce oi the spring passes from one side to the other ol the pivots luy which the switch carrying ineinher is connected to the supporting hars 56 .causingl the switch to snap and turn from the position` shown il to s. positionwliere it will he tilted in the opposite direction. The contact. ot the lower ends' ot the screws 62 with tlie upper edge oi the har ddirectly below., limits .the extent olf/tilting movement of the tuhe 45.

'The construction ot the class described is automatic in its'action,.is dura-ble and eicierit and not liable to get out o order9 is easily ad-f justed to change the range, and the bellows element which is the only part of the mechanism which may possibly `tail, can he very` readily removed for repair or replacement lll() hy a new element of the same lrind. The

spring i4 which may he termed the rangeW I spring is used foi-'regulation oit the range oit l pressure between stopping and starting pressures. yIt usually is adjusted to a fixed position when it leaves the factory9 which position does not thereafter need to be changed.

e spring 18 which may be termed the Ftemperature by its tension determines` the pressure at which the switch will tilt to off plosition, it at all times beingin direct opposition to the force of the bellows 23 against the lever '8.- The pressure in the .bellows must be suftcientto overcome the :torce oi both ol the springs before the lever will be moved tar enough to tilt-the tube toa position where the circuit is completed.' yThe maximum range between stopping and starting pressures is attained'when the-spring it Tis adJusted to maintain tension against the lever 8 until said lever is almost\1n position,

necessary to tilt the tube Llf3 from its on to its oli position'. The minimum range lis attainedwlienuthe spring it does .noten-l .i l ert pressure against the lever 8'. An adjustment' of the nut 22, so as to increase the tension in spring 18, will apply more torce to the ylever 8 in which case a higher temperature in the refrigerator may be had.y -fls said be- 1 lore ythe spring lli .is .seldom adjusted. i However, should it bedesirable to startftherunit at a higher pressure operation of the control it can be very readily adjusted. The :tarther the spring it is moved awayc from the lever 'S'the lower will be the pressure 1at which the motor starts.

By reason of the manual cont-rol of the lever 8 through `the crank handle ila and the r rod llpi? which it is a part, it is readily pos-` prehensive oi all sible to hold ,the switch in either its oli or its on position irrespective ci what may vbe the condition oi pressure inthe refrigerating machine. At the neutral orl intermediate point the apparatus is permitted te acty automatically. There are 'inany2 times when .it is desirable to prevent the motor :trom running irrespective ci pressure and also other times when it is desired to have it continuously running, and by reason of the manual control described either of these conditions may be very easily had.

rlhisc-enstruetion has been teste/d and tried extensively and has proved its practieability in such tests.. The invention is deiined in the appended claims and is .to be considered coiniorins of structureV coming within their scope.

l., ln a construction of the class described, a housing support having a base, vertical side and a vertical end, said side at its lower portion near one end having an opening therethrough, an arm pivotallyy mounted at its lower end on said base, spring means acting onthe arm to turn it in one direction, a

corrugated metal bellows located in said housing opposite said opening in the vertical end . 'longitudinally thi' incapace side thereof and having one end bearing against the lower portion of the arm andthe opposite end secured to the'adjacent vertical of the housing whereby vsaid bellows may. be readily replaced or removed through said opening,`and a cover detachably connected to the housing over said opening. 2. construction containingthe elements in combination dened in, claim l, said arm at one side having a member extending laterally therefrom throughwhich an opening isinade, a shaft rotatably mounted on lpassing' through the vertical side olilthe housing, and means on the inner end of the shalt located in the opening in said member whereby, when said shaft i turned,said member may be fixed against inove'ment at'either ot the two extremes of its movement, said ineinber when occupying an intermediate position leaving'the arin ii'ee to be acted upon by the bellows and said spring means.

3. .ln a construction lof the class described, a housing support having a base, a 'vertical end, and a vertical side, said vertical side at its lower portion adjacent the end having an opening therethrough and said vertical end having a horizontal slot formed therein. in- Nrvvardly for a distance troni the edge of said opening, an armv pivotally mounted on said support a'short distance above the base andentending vertically, spring means tending to move the arm atits upper end toward the vertical end of the support, a corrugated metal bellovvs located between the lower end portion ot the arm and said end of the snp-f port having one end bearing against the arm, l a tubular member entering and connected f the opposite end of said bellows seate` said slot, a cover for the opening detacha y connected to and onl the outer side oi the vertical side et the support, and a. switch for inalring and breaking an electric circuit op? eratively connected with the arm to be moved thereby, substantially as described..

ln combination, a housing support hav- Cing a. base, a vertical side and a vertical end, an arm pivotally mounted its lower endonsaid. support ashort` distance above the base, a rod passing through said end oi the liousthe upper end ot' 'the arin,

ing and through said rod being threaded at its innerend, nuts s threaded on the inner end of the 'roda coinbetiveen thc arni adjusting 2the rod ough the said end. ot the suppoitpa second/spring connectedat vonev end to the arm a-distance below the upper end thereof, a nut secui'edgat the opposite end ot the spring, a `rod passing through the end ot the vsupport and threaded through said nut, means on the outer end of the rod for turning the saine, a movable. switch operatively connected with the arin to move from circuit making to circuit breaking position or vice versa with the movements oit the arm,

pression spring on said rod and-the nuts, means flor ias ias'

n corrugateci metal beliows subject to inner variations of pressure connected at one lenti to the enti of 'the housing and at its opposite end bearing against saici arm a short distance above its pivota and means manually operabie from outside of the housing for locking the leven Vegemnst movement at either extreme of its movements whereby the switch wiii be heid eithei in circuit making or breaking positiou irrespective of the condition of piessuie in said. bellows.

' In testimony whereof i aiiix my signatureo mtos PQ HEATH 

